The present invention relates to an apparatus for sensing a load, and more particularly, to an apparatus for sensing the load imparted to a vehicle seat by a vehicle occupant.
A conventional vehicle occupant load sensing apparatus includes a load sensor placed between a vehicle seat frame and a support mount for the seat. The sensor is directly within the vertical load path of the occupant""s weight and responds to the vertical loads imparted to the seat by the occupant of the seat. In addition, the sensor may respond to torque loads between the seat and the support mount. Since the seat frame and the support mount must withstand large torque loads (i.e., tilting of the seat frame during crash conditions), typically the sensor also must be constructed to withstand large torque loads.
This construction lessens the sensitivity of the sensor in the vertical load path. Thus, the sensor may not produce a reliable vertical load output signal.
A load sensing apparatus which decouples the torque and vertical loads would allow the construction of a load sensor that does not have to withstand torque loads and thereby may be more likely to produce an accurate occupant load output signal related to upward and downward loads in the vertical load path.
The present invention relates to an apparatus for use in a vehicle having a seat for a vehicle occupant and a vehicle floor pan for supporting the vehicle seat. The apparatus includes a vehicle seat frame, a bracket, a first member, a second member, a lever, and a sensor. The vehicle seat frame supports a load of the vehicle occupant in the vehicle seat. The load of the vehicle occupant in the vehicle seat is transmitted through the bracket from the vehicle seat frame to the vehicle floor pan. The first member is interposed between the vehicle seat frame and the bracket. The first member is compressible as the seat frame moves downward and is expandable as the seat frame moves upward. The second member is interposed between the vehicle seat frame and the bracket. The second member is compressible as the seat frame moves upward and is expandable as the seat frame moves downward. The lever has a first end portion movable with the seat frame and a second end portion associated with the bracket. The lever bends as the seat frame moves vertically relative to the bracket. The sensor detects bending of the lever and provides an output signal indicative of the amount of bending of the lever.
Another feature of the present invention includes a bracket having a first curved engagement surface engaging an upper surface of the lever. The bracket further includes a second curved engagement surface engaging a lower surface of the lever.
Still another feature of the present invention includes a fastener with a longitudinal axis and a fastener member rotatable about the longitudinal axis. The fastener secures together the seat frame, the bracket, a member, and the lever. The bracket and the seat frame have cooperating engaging portions that inhibit rotation about the longitudinal axis of the bracket when the fastener member is rotated about the longitudinal axis.
Yet another feature of the present invention includes a bracket having a first portion for connection with the vehicle floor pan and a second portion for connection to the seat frame. The bracket further includes a hinge for allowing relative vertical movement between the first and second portions of the bracket during installation of the bracket onto the seat frame.